Question

Fie functia F : R --> R
f (x) = -2x +5
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Calculati suma S = f(-5) + f(-4) + f(-3) +.........+f(10)

Answer 1

Explicație pas cu pas:

f(-5)=15

f(-4)=13

f(-3)=11

f(10)=-15

S = f(-5) + f(-4) + f(-3) +.........+f(10)

S=15+`13+11+...+(-15)

n=(-15-15)/2+1=-14

S=-14(-15+15)/2=0